This invention relates to cathode ray tubes and to a faceplate for use therewith. More particularly, this invention concerns itself with a cathode ray tube face plate particularly adapted to bring about charge transfer from the electron beam generated within the tube to any controlled media positioned outside the tube.
A cathode ray tube is an electron tube in which a beam of electrons can be focused on a surface to present information in the form of a pattern of light. The particular pattern is determined by sweeping electrical signals from an electron gun positioned within the body of the tube across the surface of the tube's faceplate. Generally the surface is luminescent and the electrical signals are converted to a predetermined visual pattern. The television picture tube is the most familiar form of the cathode ray tube.
However, other cathode ray tubes are utilized that do not produce a visual pattern but, instead, transmit the electric signal from the electron gun through the face plate of the tube to provide a charge transfer to an ancilliary recording device positioned outside the tube itself. Unfortunately, the tubes designed to accomplish this type of charge transfer do not provide good resolution. With the present invention, however, a cathode ray tube faceplate fabricated from commercially available boron fibers would provide a simple and convenient means for effecting a charge transfer from the electron beam within a cathode ray tube to a controlled media outside while still maintaining a vacuum in the cathode ray tube. In addition, the device of this invention provides high resolution up to about 30,000 dots per square inch (.about.170 dots/inch on each axis). The use of the faceplate of this invention would find wide use in electronic printing, optical modulation, projection displays, real time optical processing, memory access, as well as for use in a variety of other electronic devices and applications.